治疗胃肠道疾病药物.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,文档仅供参考，不能作为科学依据，请勿模仿；如有不当之处，请联系网站或本人删除。,消化性溃疡（,peptic ulcer,）为消化系统最常见疾病，发病率约,8%10%,。为一种慢性疾病，可反复发作，病情持续数年至数十年，可发生于消化道任何部位，最多见于胃和十二指肠溃疡。,胃溃疡,多位于胃小弯近幽门处，,十二指肠溃疡,一般位于球部。,消化性溃疡,一、病因及发病机制,溃疡病的发病机制过去过于强调胃酸和胃蛋白酶的攻击作用，后来开始重视粘膜屏障、细胞保护因子、局部血液循环等抗溃疡因素。正常情况下两者处于平衡状态，当致溃疡因素作用超过抗溃疡因素，两者不平衡时就易发生溃疡。,攻击因子（致溃疡因素）,胃酸过多：各种刺激引起胃酸和胃蛋白酶分泌，产生自身消化作用。有“无酸不成溃疡”的说法。,幽门螺杆菌,（,Helicobacter pylori,Hp,）：寄生在胃粘液层之下，破坏粘液层，减弱其保护作用。是溃疡病长期不愈，反复发作的重要因素。,药物：,阿斯匹林及非甾体类抗炎药,胆汁和十二指肠液的反流：可破坏胃粘膜，刺激,G,细胞分泌胃泌素促胃酸分泌。,防御因子（抗溃疡因素）,粘膜屏障：粘液,-,碳酸氢盐屏障（胃腔中,pH,常,/=3 mm in size with depth,that can involve the stomach(gastric ulcer)or duodenum(duodenal ulcer).The most important contributing factors are,Helicobacter pylori,nonsteroidal anti-inflammatory drugs(NSAIDs),acid,and pepsin.,Although peptic ulcers produce a variety of symptoms,none is specific for the disease.Severe pain or a rapid increase in pain suggests an ulcer complication or another diagnosis;,associated dyspepsia symptoms include nausea,bloating,heartburn,and belching.Indeed,peptic ulcers are the most common cause of acute upper GI bleeding,H pylori,eradication and/or antisecretory therapies are the mainstay of todays treatment strategies.,四、治疗溃疡病药物分类,（一）治疗溃疡病药物的评价,治疗溃疡病主要有,4,个有目的：,（,1,）控制症状；,（,2,）促进溃疡愈合；,（,3,）防止并发症发生；,（,4,）防止溃疡复发。,现今的所有抗溃疡药物均能达到（,1,）和（,2,）的目的，有的还可减少并发症，如出血，穿孔等。但现有的抗溃疡药物都不能彻底根治溃疡病，而杀灭幽门螺旋杆菌的药物能大大降低复发率。,抗酸剂：,氢氧化铝，三硅酸镁，碳酸钙等，起中和胃酸作用，现已很少用。,抑制胃酸分泌：,H,2,受体阻断剂：西咪替西，雷尼替丁，法莫替丁,H,+,-K,+,-ATP,酶抑制剂（质子泵抑制剂）：奥美拉唑，兰索拉唑,其他还有,M,受体阻断剂和胃泌素受体阻断剂,胃粘膜保护剂：,前列腺素,E,，枸橼酸铋钾，硫糖铝,杀灭幽门螺杆菌：,三联疗法：枸橼酸铋、甲硝唑、羟氨苄青霉素,二联疗法：奥美拉唑、甲红霉素，或加羟氨苄青霉素三联疗法,Acid Peptic Diseases Pharmacological Approach to Treatment,Modulating Gastric Acid,抗酸药物的发展,Beginning with antacids,histamine type-2 receptor antagonists(H2RAs),and sucralfate,there has been a steady development of effective therapies for these conditions,culminating with the proton-pump inhibitors(PPIs),Antacids,现已用得越来越少了，大多被H2RAs和PPIs取代。,特点：,They are inexpensive,readily available,and safe in most populations.,Antacids work nearly instantaneously and find utility for rapid relief of mild or sporadic symptoms.,The effective time for antacids to reduce stomach acidity is relatively short on an empty stomach.,calcium carbonate,sodium bicarbonate,magnesium hydroxide and aluminum hydroxide.hydrotalcite铝碳酸镁,H2-receptor Antagonists,The H2RAs are reversible structural analogs of histamine that cause a decrease in the tonic activation rate of the receptor,thus,these agents act as inverse agonists with a functional antagonism of histamine activity.,Cimetidine,ranitidine,famotidine and nizatidine.,（西咪替丁为肝药酶抑制剂，有抗雄激素作用）,特点：,H2RAs mainly inhibit basal rate of acid release during nonfeeding periods.This is of particular importance during the nocturnal periods of fasting,which is the rational for the use of H2RA dosing at bedtime.The H2RAs are often administered once a day prior to bedtime to maximally impact nocturnal basal acid secretion.,All agents have linear pharmacokinetics and are eliminated primarily by renal mechanisms.Dose adjustments are needed for patients with renal impairment.,H2RAs are superior to placebo,but inferior to PPIs for the treatment of esophageal reflux disease.,Histamine receptor antagonists have modest efficacy in nonulcer dyspepsia,however,they are not as effective as PPIs.,Proton Pump Inhibitors,PPIs are weak bases that act as prodrugs and need an acidic environment in order to inhibit the H+K+-ATPase.,PPIs accumulate in the secretory canaliculus of the parietal cell.,The PPI becomes protonated and converted into the active sulfenamide species,which forms disulfide bonds with cysteine residues in the-subunit of the H+K+-ATPase.,By contrast,with H2RAs,PPIs also decrease pepsin secretion,which serves to reduce mucosal damage.,Morning dosing of PPIs is associated with significantly improved acid suppression.PPIs should be administered before breakfast.,The effects of the PPIs increase with repeated administration and,generally by the third day.,PPIs undergo metabolism via hepatic CYP2C19.Of the PPIs,rabeprazole is unique as only 15-20%of its metabolism involves the CYP system.There is differential metabolism between individuals due to pharmacogenetic variation.,Possible associations with hip fractures,renal complications and community-acquired pneumonia have also been demonstrated.,The long-term safety of the class include prolonged hypergastrinemia,the possible association of PPIs with gastric atrophy and chronic hypochlorhydria.,PPIs should not be administered concomitantly with H2-antagonists,prostaglandins or other antisecretory agents owing to the marked reduction in their acid inhibitory effects when administered simultaneously.,Mucosal Protective Agents,Sucralfate,It is a nonabsorbable medication that binds to gastric mucosa and ulcerated tissue.These properties favor healing and provide cytoprotective effects.,Sucralfate has similar efficacy in healing of duodenal ulcer and gastric ulcers when compared with H2RAs.,The primary utility is in the prophylaxis of stress ulceration in critically ill patients.,sucralfate is best avoided in patients with kidney failure,PPIs,抗泌酸作用强，并可用于上消化道出血等,PPI infusion and high-dose oral therapy in the setting of bleeding PUD have been common practices for the last several years.,The use of intravenous formulations of PPIs prior to endoscopy in patients with bleeding PUD.,PPI,抑制夜间泌酸改善症状,After 1.4 months of pantoprazole(40 mg daily)therapy,any sleep disturbances had improved in more than 75%of patients,with resolution of nighttime heartburn and nighttime regurgitation in 73%and 84%of patients,respectively.,PPI,新剂型增强药效,AGN,the enteric-coated novel PPI,was shown to provide faster and more profound acid suppression than esomeprazole on day 1 and also at day 5,the time point that both medications should have reached steady state.Both medications were well tolerated and no adverse events were reported.Nocturnal acid suppression was also greater by 2 pH units after 5 days,长期使用,PPIs,的不良反就应,Adverse Effects of Proton Pump Inhibitor Drugs:Clues and Conclusions,H2,抑制剂和铋剂,Recommendations for Treating Peptic Ulcer Disease,Helicobacter pylori,infection be eradicated and antisecretory therapy,preferably with a proton pump inhibitor(PPI),be given for 4 weeks;,patients with persistent symptoms should undergo endoscopy.,根除,Hp,有助于病愈及防止复发,To facilitate healing and to decrease the risk for recurrence of gastric and duodenal ulcers,H pylori,should be eradicated in patients with peptic ulcer disease.,PPIs,抗酸效果较其它药好,PPIs offer suppression of acid secretion,healing,and symptom relief in patients with peptic ulcers that are superior to those associated with other antisecretory therapies,溃疡出血应用,PPIs,Patients with bleeding peptic ulcers should be treated with a PPI to decrease the need for transfusions or surgery and to reduce the duration of hospital stay.Those with bleeding peptic ulcers and positive,H pylori,testing should have eradication therapy prescribed,穿孔性溃疡也应根除,Hp,Patients with perforated ulcers should undergo eradication of coexisting,H pylori,infection.Successful eradication should reduce the need for long-term antisecretory therapy and additional surgery,Patients with peptic ulcers who are older than 55 years,have alarm symptoms,or have ulcers that fail to respond to treatment should promptly undergo upper endoscopy,注意恶变,肠易激综合征,Irritable Bowel Syndrome,是一组包括腹痛、腹胀、排便习惯改变和大便性状异常、粘液便等表现的临床综合征，持续存在或反复发作，经检查排除可以引起这些症状的器质性疾病。,本病是最常见的一种功能性肠道疾病。,临床表现,最主要的临床表现是腹痛与排便习惯和粪便性状的改变。,腹痛,几乎所有,IBS,患者都有不同程度的腹痛。部位不定，以下腹和左下腹多见。,腹泻,一般每日,3,5,次左右，少数严重发作期可达十数次。大便多呈稀糊状，也可为成形软便或稀水样。部分患者腹泻与便秘交替发生。,便秘,排便困难，粪便干结、量少，呈羊粪状，表面可附黏液。,其他消化道症状 多伴腹胀或腹胀感，可有排便不尽感、排便窘迫感。,全身症状 相当部分患者可有失眠、焦虑、抑郁、头昏、头痛等精神症状。,体征 无明显体征，可在相应部分有轻压痛，部分患者可触及腊肠样肠管，直肠指检可感到肛门痉挛、张力较高，可有触痛。,肠易激综合征类型,便秘型：伴有周期性便秘与较频繁的正常大便交替，大便经常有白色黏液，疼痛呈绞榨样，阵发性发作，或持续性隐痛，排便后可缓解。进食常会促发症状，也可以出现腹胀、恶心、消化不良和烧心等症状。,腹泻型：特别是在进食刚开始，或结束时出现突发性腹泻。夜间腹泻很少，常有疼痛、腹胀和直肠紧迫感，也可出现大便失禁等情况。,治 疗,一般治疗,建立良好的生活习惯。饮食上避免诱发症状的食物，因人而异，一般而言宜避免产气的食物如乳制品、大豆等。高纤维食物有助改善便秘。对失眠、焦虑者可适当给予镇静药。,药物治疗,胃肠解痉药：抗胆碱药物，胃动力药，5-HT3拮抗剂,止泻药：洛哌丁胺，思密达、药用炭等,泻药：对便秘型患者酌情使用泻药，但不宜长期使用。半纤维素或亲水胶体，在肠腔内吸水膨胀增加肠内容物水分及容积，起到促进肠蠕动、软化大便的作用，被认为是治疗IBS便秘比较理想的药物,。,Pump Inhibitors,Irritable Bowel Syndrome,and Small Intestinal Bacterial Overgrowth,the role of antibiotics vs.conventional pharmacotherapy in treating symptoms of irritable bowel syndrome.Aliment Pharmacol Ther 25,12711281;2007,慢性胃炎,病因病机：,80%,以上的成年人具有不同程度的浅表性胃炎。浅表性胃炎和糜烂性胃炎主要由烟、洒、刺激性食物和药物，胆汁反流和幽门螺杆菌等引起。萎缩性胃炎则还与自身免疫反应，胃粘膜反复受损，胃腺萎缩有关。,主要临床表现：,上腹不适、胃痛、食欲不振、嗳气及腹胀等。一般无明显体征。,分 型：,浅表性胃炎：胃镜下见散在胃粘膜水肿、斑点状出血、糜烂，显示红白相间。腺体与粘膜厚度多数正常，肠上皮化生很少。,糜烂性胃炎：病变范围深于浅表性胃炎。粘膜上有多个,5-10mm,大小的疣或丘疹样隆起，中央糜烂，病变多见于胃窦部。,萎缩性胃炎：胃镜下粘膜色泽红白相间，而以白相为主。粘膜萎缩变薄，腺体萎缩，胃酸低下，腺上皮化生多，可能出现恶性贫血,pernicious anemia,或癌变,。,诊断依据：,依靠胃镜检查和胃粘膜病检。,治 疗,：,保护胃粘膜和对症治疗。幽门螺杆菌感染者杀菌。,Chronic gastritis associated with,Helicobacter pylori,infection,Left:An antral gland of the stomach with a large colony of Helicobacter pylori in the lumen(arrow).Right:A transverse section of the gastric lamina propria is shown.In the lower part,an antral gland of the stomach is present with some Helicobacter pylori in the lumen(red-blue arrow),while in the upper part a mast cell(yellow arrow)is present.,幽门螺杆菌,胃腺萎缩,萎缩性胃炎,肠,上皮化生,胃癌,幽门螺杆菌,胃窦炎、十二指肠炎,十二指肠溃疡、胃溃疡,对幽门螺杆菌若干问题共识意见,（安徽桐城会议,2003,）,Hp,感染及其相关疾病,流行病学调查证实,Hp,在有些国家或地区的人群中，感染率仍很高,.,胃是,Hp,在人体内定植的主要部位，我国不同地区、不同民族人群胃内,Hp,检出率在,30-80%,之间，有很大差别。,1,Hp,是慢性胃炎和消化性溃疡,(PU),的重要致病因子,。,2,Hp,与胃癌的发生有关,:,(1),Hp,可增加胃癌发生的危险性,.,(2),Hp,根除后可阻断或延缓萎缩性胃炎和肠化的进一步发展，但是否能使两种病变逆转尚需进一步研究,.,(3),Hp,根除后可降低早期胃癌术后的复发率,.,(4),在亚太地区如日本、韩国和中国，绝大多数,Hp,菌株均为,cagA,阳性菌株,其在消化性溃疡、胃癌和慢性胃炎中的阳性率无显著差异。,(5),胃癌的发生是一个多步骤过程，从慢性胃炎经过萎缩、肠化生和不典型增生，最后到胃癌,.,胃癌的发生是,Hp,感染、宿主因素和环境因素共同作用的结果,.,cytotoxin-associated gene(cag),3,Hp,是胃黏膜相关淋巴组织,(MALT),淋巴瘤重要的致病因素，,Hp,感染是,MALT,淋巴瘤产生的原因，胃,MALT,淋巴瘤在,Hp,高发区常见、多发,.,根除,Hp,可以治愈早期胃,MALT,淋巴瘤，染色体分析提示胃,MALT,淋巴瘤的发生可能具有遗传性,.,4,Hp,与非甾体类抗炎药,(NSAID),是消化性溃疡发生的两个重要独立危险因素，单纯根除,Hp,不足以预防,NSAID,溃疡，初次使用,NSAID,前根除,Hp,可降低,NSAID,溃疡的发生率，使用,NSAID,过程中根除,Hp,不能加速,NSAID,溃疡的愈合,.,5,Hp,与胃食管反流性疾病,(GERD),的关系尚无肯定结论,.,6,Hp,感染和功能性消化不良,(FD),的关系仍未明确,.,Hp,感染的治疗,一线方案,:,(1)PPI/RBC(,标准剂量,)+A(1.0)+C(0.5),，,Bid7 d;,(2)PPI/RBC(,标准剂量,)+M(0.4)+C(0.5),，,Bid7 d;,(3)PPI/RBC(,标准剂量,)+A(1.0)+F(0.1)/M(0.4),，,Bid7d;,(4)B(,标准剂量,)+F(0.1)/M(0.4)+C(0.5),，,Bid7 d;,(5)B(,标准剂量,)+M(0.4)+T(0.75-1.0),，,Bid14 d;,(6)B(,标准剂量,)+M(0.4)+A(0.5)Bid14 d.,代号说明,:PPI(,质子泵抑制剂,):,目前有埃索米拉唑,(E),、雷贝拉唑,(R),、兰索拉唑,(L),、奥美拉唑,(O);RBC(,枸椽酸铋雷尼替丁,);A,阿莫西林,;C,克拉霉素,;M,甲硝唑,;T,四环素,;B,铋剂,(,枸椽酸铋钾、果胶铋等,);F,呋喃唑酮,.,也可以,H,2,受体阻断剂,(H,2,RA),替代,PPI(,如,:,西米替丁、雷尼替丁、法莫替丁,).,但根除率可能会有所降低,.,二线方案,:(1)PPI(,标准剂量,)+B(,标准剂量,)+M(0.4 Tid)+T(0.75-1.0),，,Bid7-14 d;(2)PPI(,标准剂量,)+B(,标准剂量,)+F(0.1)+T(0.75-1.0),，,Bid7-14 d.,Hp,阳性的下列疾病,必须,支持,不明确,消化性溃疡,1,v,早期胃癌术后,v,胃,MALT淋巴瘤,v,明显异常的慢性胃炎,2,v,计划使用,NSAIDs,v,部分,FD3,v,GERD3,v,胃癌家族史,v,个人强烈要求治疗者,v,胃肠道外疾病,v,1,PU:,无论活动或非活动，无论有无并发症,.,2,明显异常,:,指合并糜烂，中,-,重度萎缩，中,-,重度肠化生，轻,-,中度不典型增生,.,重度不典型增生应考虑癌变,.,3,FD,和,GERD,应根除,Hp,的理由如前所述,.,表,2,Hp,感染治疗适应证,幽门螺杆菌感染和环氧化酶,-2,表达在胃癌发生中的作用,1,Hp,感染与胃癌及癌前病变,流行病学资料提示长期,Hp,感染可导致胃黏膜的萎缩、肠上皮化生及异型增生，最终形成胃癌。,因此，,1994,年世界卫生组织国际癌症研究机构已正式将,Hp,列为第一类生物致癌因子,。,近年来动物实验研究、胃黏膜上皮细胞培养和,Hp,根除干预实验等均证实了,Hp,感染致胃癌的危险性,。,Hp,细胞毒素相关基因,A(,cagA,),阳性菌株具有更强的毒力和危险性，,cagA,+,菌株感染后胃黏膜上皮细胞损害明显并影响壁细胞的分泌功能，导致胃酸分泌减少，胃内细菌过度生长，促使硝酸盐降解为亚硝酸盐和亚硝胺等致癌物,。,2,Hp,感染诱导,COX-2,的表达,Hp,感染和,COX-2,表达在胃癌的发生、发展中均起重要作用，,Hp,作为促癌因子诱导,COX-2,表达，,Hp,感染者胃黏膜中,COX-2,表达明显增加,。,Hp,感染相关的急、慢性胃窦炎的胃上皮细胞和单核细胞中,COX-2,蛋白表达增加,.,虽然根除,Hp,减少胃黏膜,COX-2,表达，但不能逆转肠上皮化生。,3 COX-2,在胃癌和癌前病变中表达增加,COX-2,与细胞增生和肿瘤发生密切相关，正常情况下,COX-2,几乎不表达或表达甚少，而在炎症因子、生长因子、内毒素和促癌剂等刺激下，,COX-2,表达迅速增加，并参与炎症过程和肿瘤的发生、发展,16,.,众多研究显示，,COX-2,在胃癌和结直肠癌中表达增加。癌组织中,COX-2 mRNA,显著高于癌周正常组织,。,4 COX-2,的致癌和促癌机制,尽管,COX-2,与胃癌的发生发展密切相关，但,COX-2,表达在肿瘤发生、发展中的作用机制尚不明确,。,COX-2,可能经多种途径促进细胞增生、抑制细胞凋亡、调节肿瘤新生血管形成和增加癌细胞的侵袭性等而发生致癌和促癌作用,。,COX-2,表达增加,PGE2,合成，,PGE2,可诱导细胞增生并刺激,Bcl-2,蛋白表达，后者可抑制细胞凋亡。,COX-2,促进,VEGF,相关的肿瘤血管生成，可能是其在致癌和促癌中发挥作用的另一重要途径,.,5,Hp,感染诱导,COX-2,表达的机制,目前，,Hp,感染诱导胃黏膜,COX-2,表达的机制尚待阐明，可能是,Hp,感染引起胃黏膜损伤刺激,COX-2,表达，也可能是,Hp,感染及其毒素直接诱导,COX-2,表达,。,国内外研究表明，,Hp,细菌悬液、超声提取物甚至,Hp,细菌培养液均可诱导培养细胞的,COX-2,表达,.,Hp,感染可能通过炎症细胞释放细胞因子的间接作用，亦可能是直接诱导胃黏膜炎症细胞表达,COX-2,，再通过旁分泌机制和信号传导引起上皮细胞表达,COX-2,。,有关,Hp,感染的新进展,Helicobacter pylori,Infection and Current Clinical Areas of Contention,NSAID,以预防溃疡的复发,。,对现患胃溃疡或既往有胃溃疡病史且正应用,NSAID,者，应用铋剂为中心的根除,Hp,的治疗方案较以,PPI,为中心的根除方案在,NSAID,相关性胃溃疡的治疗和预防中有更好的疗效,。,对,Hp,阳性的有胃肠症状的阿司匹林应用者，如果需要继续应用阿司匹林，根除,Hp,会减少患者溃疡出血的危险性,;,如果无消化不良症状或无溃疡病史，则没有必要检测,Hp,或根除,Hp,治疗,.,如果患者即将应用,NSAID,，检测并根除,Hp,将肯定会减少溃疡的危险性,.,应用选择性,COX-2 NSAID,的患者，有关,Hp,根除的建议与未应用,NSAID,者相同,.,在长期应用,NSAID,者，根除,Hp,和随后的,PPI,预防疗法将肯定减少溃疡的发生和复发，促进溃疡的愈合,.,Withdrawal of Vioxx Casts a Shadow Over COX-2 Inhibitors,the COX-2 inhibitor Vioxx,off the market after an alarming pattern surfaced halfway through a 3-year colon polyp prevention study.Heart attacks and strokes had occurred at a much higher rate among the roughly 1300 volunteers on Vioxx(3.5%)than among the 1300 taking a placebo(1.9%).,www.sciencemag.org/cgi/content/full/306/5695/384,Vioxxs propensity to trigger heart attacks and strokes isnt fully understood.But some experts believe that its valued mechanism-specifically,its ability to suppress a narrow set of molecules that mediate inflammation-may have been its downfall.,Anti-inflammatory drugs like naproxen suppress both prostacyclin,which plays a role in inflammation,and thromboxane.But COX-2 inhibitors block only prostacyclin;this may tilt the balance in favor of thromboxane and,potentially,blood clotting.So far the thrombosis theory has been supported only by animal studies.,A study showed that rofecoxib(Vioxx),compared here to naproxen,could cause cardiovascular problems.,ADAPTED FROM D.MUKHERJEE,ET AL.,JAMA,286,8(2001),